Tank cleaning apparatus



E. T. YOUNG sem. 19, 1967 TANK CLEANING APPARATUS 2 Sheets-Sheet l Filed Aug. 18, 1955 INVENTOR. EHNAR YOUNG f/ ,f x f E. T. YOUNG Sept. 19, 1967 TANK CLEANING APPARATUS 2 Sheets-Sheet 2 Filed Aug. 18, 1965 n?. .Illllll I isili.

All/1 INVENTOR. EENAR T. YOUNG Unted States Patent O 3,341,880 TANK CLEANING APPARATUS Einar T. Young, Newtown Square, Del., assignor to Sun Gil Company, Philadelphia, Pa., a corporation of New `Ierse y Filed Aug. 18, 1965, Ser. No. 480,698

8 Claims. (Cl. 15-257) ABSTRACT F 'EHE DHSCLGSURE For cleaning underground storage tanks, a vertical standpipe slotted at its lower end and carrying a springbiased pivotally-rnounted guiding member which can extend outwardly through said slot, is pushed downwardly through the tank until its lower end, and also the outer end of the guiding member, engage the tank bottom. A flexible hose, to the outer surface of which is adhesively secured a spring steel stiifening tape, is pushed down through the standpipe, its lower end being guided by the guiding member outwardly through the slot and along the tank bottom. The upper end of the hose is connected to a suction pump.

The present invention relates to tank cleaning apparatus, and more particularly to means for removing from liquid storage tanks (such, for example, as underground storage tanks used for fuel oil, gasoline, etc.) the scale, sludge, sediment, rust, or other solid material which collects or is deposited therein during use, as well as the water and other extraneous liquids which may accumulate at the bottom of such tanks.

An object of this invention is to provide a new and improved apparatus for rapidly and effectively cleaning fuel oil or gasoline tanks or tanks for containing other liquids, particularly that type of tank wherein only Ia small opening (to wit, the opening ordinarily used for gauging the tank) is available for the insertion of cleaning tools.

Another object is to provide a novel tank cleaning apparatus which can be readily inserted through the relatively small opening normally employed for gauging underground gasoline tanks or the like, and which can be readily manipulated to effectively remove scale, rust, sediment, sludge, or water from the bottom of the tank.

A further object is to provide a novel easily transportable apparatus for cleaning underground storage tanks, such as the gasoline storage tanks installed at service stations.

Briefly, the apparatus of this invention includes a standpipe which pivotally carries, near its lower end, a springbiased hose-guiding channel. The standpipe is lowered down through the gauge tube of the tank to be cleaned, until it contacts the bottom wall of the tank; the channel, under the urging of its spring, swings outwardly as the pipe is being lowered and its free end comes to rest on the tank bottom such that this channel makes an angle of about 60 with the axis of the pipe. The apparatus also includes a reel carrying a hose assembly which is flexible but which has substantial stiffness in the direction of its length, and a suction pump coupled to the inner or reel end of the hose assembly. The outer or free end of the hose carries a nozzle. This reel is fastened to the upper end of the standpipe after the latter is in position in the tank, and the hose assembly, nozzle end first, is fed downwardly through the standpipe. As the hose reaches the lower end of the standpipe, the nozzle contacts the hose guiding member or channel, and is caused by this channel to turn and move horizontally along the bottom wall of the tank. The suction pump is started and, as the lower section of the hose is fed outwardly along the bottom of ice the tank, the foreign material (water, sediment, etc.) is drawn up out of the tank through the nozzle and hose to the surface.

A detailed description of the invention follows, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a view Ipartly in section illustrating a portion of an underground tank with which the tank cleaning apparatus of this invention is adapted to be used, showing the tank cleaning apparatus in position for cleaning the tank;

FIG. 2 is a transverse cross-section of a hose assembly, taken on line 2 2 of FIG. l;

FIG. 3 is a view, partly broken away and on an enlarged scale, of the free end of the hose assembly, showing a nozzle attached thereto;

FIG. 4 is a top view of the apparatus of FIG. l, showing the reel in position at the top of the standpipe; and

FIG. 5 is a horizontal cross-section taken on line 5-S of FIG. 1.

Sludge, sediment, and other refuse (extraneous or foreign) materials accumulate on the bottom and side walls of tanks used for containing fuel oil, gasoline, or other liquid materials. This sludge and sediment collects or is deposited, in particular, on the bottom and side walls of gasoline tanks and the invention will be described in this connection, although it will be understood that the apparatus has other uses. The sludge consists of scale and rust which form on the inside of the tank and tend to gradually drop to the bottom of the tank. In addition, sediment accumulates from the gasoline. Moreover, because of temperature changes, condensation occurs on the inside of the tank; the resulting water accumulates and, of course, settles at the lowest point in the tank, since its specific gravity is higher than that of the gasoline.

The sludge or sediment produced by this mixture of materials is extremely ditiicult to remove from the tank bottom and walls, particularly in the case of a tank for the storage of gasoline. The sludge or sediment, as well `as the water, should be removed from a gasoline tank, as they are likely to be drawn through the suction line toward or to the customers gasoline tank, with the result that his fuel line strainer, or his fuel line, are likely to become clogged, or contaminated with water. The apparatus of this invention has been developed for the purpose of removing such sludge, sediment, water, or other waste materials accumulating in fuel oil, gasoline, or other liquid storage tanks, particularly of the underground type.

In FIG. 1, the numeral 1 indicates the bottom wall of an underground gasoline storage tank. While the invention is shown, in this particular view, as applied to an underground tank, it will be appreciated that this is merely for purposes of illustration, and that the apparatus shown may be used with tanks otherwise located. The tank may be of any desired size or shape, although usually gasoline storage tanks are cylindrically shaped. The apparatus, by way of illustration, will be described, insofar as its operation is concerned, in connection with the cleaning of tanks having a bottom with upwardly curving side walls, since this is the most usual type encountered. When the tank is buried beneath the ground level 2, the gauge tube 3 for the tank (which tube is yordinarily located near one end of the tank, the lower end of tube 3 being secured as at 45 to the top 47 of the tank) projects upwardly from the tank substantially to ground level, and is normally covered by a cap (not shown). The upper end of tube 3 is secured firmly in the earth, as by means of asphalt or concrete formed in situ around the tube.

The apparatus for removing the sludge, sediment, water, or other waste (extraneous) material from the tank comprises, in general, a exible member or hose assembly 4, a s-tandpipe 5 adapted to be positioned within tube 3, and a nozzle 6 connected to the hose. The nozzle and the exible member or hose are adapted to be guided over the bottom 1 and portions of the side walls of the tank by the standpipe 5, as will be described, and when in use, the hose assembly 4 is positioned within the major portion of the length of standpipe 5.

The ilexible member or hose assembly 4 (FIG. 2) comprises a flexible hose 7 of the elastomeric material known as neoprene, 1/2 inch in LD. and some fifty feet in length, having a curved spring steel tape 8 (whose length is comparable to but somewhat less than that of the hose) cemented (as indicated `at 9) to the hose, by means of a suitable adhesive such as an epoxy or polysuliide resin. Due to this construction, the hose assembly is flexible, yet has substantial stiffness in the direction of its length. That is to say, the tape 8 holds the hose 7 substantially rigid in one direction or in one plane, while permitting it to flex substantially freely in that plane.

A nozzle 6 is secured to one end of the hose assembly 4, by means of a pair of screws 10 (FIG. 3) which pass through openings in the tape 8 and thread into suitable tapped holes provided in the body of the nozzle 6. Nozzle 6 has therein a bore 11 of the same diameter as the LD. of the hose 7. Beginning at the end of the nozzle which is adjacent hose 7, the major portion of the length of bore 11 is aligned with the hose opening; near its opposite end, the nozzle bore includes a portion 11a which extends downwardly at an angle of 30 to the remainder of the bore, toward the longitudinal center line (extended) of tape 8. This brings the outer end of the nozzle bore quite close to the `tank bottom 1 when the hose assembly is in operative position, since when hose assembly 4 is in use the tape 8 is toward the bottom of the tank, with the heads of screws 10 essentiallyT in contact with the tank bottom (see FIG. 1).

For convenience of handling and transporting, the hose assembly 4 is mounted on a reel 12 which will be referred to further hereinafter. The end of hose 7 opposite to nozzle 6 has thereon a hose coupling 13 (FIG. 4) which threadedly engages a pipe fitting 14 mounted in the stern of a T 15 positioned at the center of reel 12. The aligned arms of the T 15 are concentric with the axis about which the reel 12 is adapted to rotate, and the stern of the T rotates about these aligned arms when the reel is rotated in the manner described hereinafter. A pipe 16 is mounted in one of the two aligned arms of the T 15, and this pipe extends through a side plate 17 of the reel 12 and is coupled into one side of a rotary pipe joint or swing joint 18. Pipe 16 rotates with the reel 12, and communicates (through T 15 and items 14 and 13) with the reel or surface end of hose 7. A solid shaft 19 is mounted in the other one of the aligned arms of the T 15.

The swing joint 18 allows rotation of pipe 16 (when reel 12 is rotated) with respect to a stationary or xed pipe 20 one end of which is coupled into the other side ofthe rotary joint 18, while maintaining fluid communication between pipes 20 and 16. The other end of pipe 20 is threaded into one end of a transparent sight tube 21 the other end of which is coupled, by means of a pipe coupling 22, to a pipe 23 which extends to the intake of a suitable suction pump (not shown). Thus, when the apparatus is positioned as shown in FIG. 1, with the reel 12 and the suction pump above the ground level 2, with the reel end of the hose 7 connected to the intake of the suction pump as described, and with the nozzle 6 adjacent the tank bottom 1, sludge, sediment, water, etc., can be drawn up by the suction pump from the bottom portion of the underground tank to the surface, via nozzle 6, hose 7, T 15, pipe 16, swing joint 18, pipe 20, sight tube 21, coupling 22, and pipe 23. The sight tube 21 enables the operator to visually monitor the material being pumped.

When the apparatus of this invention is being transported, for example on a truck, the entire length of the hose assembly 4, including the nozzle 6, is wound on reel 12, as indicated by phantom lines in FIG. l. Then, a keeper spring 24, for example an ordinary screen door spring, is utilized to keep the hose from becoming unwound from the reel. One end of spring 24 is attached to rotary joint 18 (which is located outside the main body of the reel) by means of a ring 25, this spring passing over the outer turns of hose on the reel and the other end of the spring being fastened to one of the side braces of the reel, at the opposite side from the joint 18, by means of a hook 26.

The standpipe 5 is about twelve feet long, and this standpipe is designed to be passed down through the gauge tube 3 and through the interior of the tank to be cleaned, until the lower end of the standpipe comes to rest on the tank bottom 1, as illustrated in FIG. 1. The standpipe, which will be described in more detail hereinafter, is part of the tank cleaning apparatus of the invention, and is transported on the truck, along with the 4reel 12 containing the hose assembly, and the suction pump. Generally, underground gasoline storage tanks at service stations are so located that the top 47 of the tank is about three feet below ground level 2, which means that the tank gauge tube 3 is about three feet long; as previously mentioned, both ends of the gauge tube 3 are firmly anchored in position. The O.D. of the standpipe 5 dits rather closely within the LD. of the gauge tube 3 over this length of about three feet, so that when the standpipe S has been placed in position in the tank to be cleaned, as illustrated in FIG. 1, the vertically-extending standpipe can serve as a suitably rigid support or mounting means for the reel 12 of hose. The upper end of standpipe 5 extends a suitable distance above ground level 2 when the standpipe is in operative position.

In operation, after the standpipe 5 has been lowered into the position illustrated in FIG. l, the loaded reel 12 is mounted on the upper end of the standpipe. A centrallyapertured pipe block 27 (whose central aperture is slightly larger in diameter than the O D. of standpipe 5), which is split or slitted at one side along a diameter of the aperture, is positioned around the upper end of standpipe 5, and is then tightened in this position by means of a bolt 28 which passes entirely through the block 27 from one side to the other thereof, this bolt passing transversely through the gap in the block and carrying at one end a threaded operating handle 29 by means of which the aforesaid tightening is effected. A predetermined orientation azim-uthal relation) between the block 27 and the standpipe 5 is effected by means of a pin 3i) (which is xedly secured to block 27 and which extends along a diameter of the aperture in this block) which enters a narrow upwardlyopening sl-ot 31 cut through the upper end of standpipe 5, at one side thereof.

In order to secure the reel 12 to block 27, to thereby mount the reel on the upper end of the standpipe 5, a pair of Outrigger arms 32, which extend at right angles to the axis of the standpipe, are positioned at respective opposite sides of block 27. Arms 32 are bolted at one end (as at 28 and 33) to opposite sides of block 27 and are bolted at their opposite ends to the lower ends of respective uprights 34 (FIG. 1) which extend at right angles to the outriggers 32. Pipe 16 passes with a loose tit through an aperture provided near the upper end of one upright, and shaft 19 passes with a loose iit through an aperture provided near the end of the other upright. Fastening means 35 (including a nut which engages threads provided on the outer end of shaft 19) holds the upper ends of the uprights 34 in position at one side of the reel, and the swing joint 18 does the same at the other side of the reel. In this manner, the stationary uprights 34 support the reel 12 and journal the same for rotation about the axis provided by shaft 19 and pipe 16. A pair of fixed angularly-extending braces 36 are provided, one at each side of the reel. One end of each brace 36 is bolted at 33 to the block 27, and the other end. of

each brace is bolted to its corresponding upright 34, intermediate the ends of the upright.

The pipe coupling 22 is secured to one of the Outrigger arms 32 by means of a block 37 whose base is bolted to the Outrigger arm 32 at the rotary joint side of the reel. Coupling 22 passes through an aperture provided near the outer end of block 37, and a set screw 38 is threaded through block 37 yat this aperture and bears against coupling 22.

At the lower end of standpipe 5, there is provided an arrangement for guiding the free or nozzle end of the hose assembly 4 (as this hose assembly is pushed downwardly through the standpipe) outwardly away from the axis of the standpipe, so that the lower or nozzle end of the hose assembly is guided to lie in a substantially horizontal position along the bottom wall 1 of the tank, with the bore portion 11a of nozzle 6 closely adjacent the tank bottom wall.

A substantially rectangular slot 39 is cut through one side of standpipe 5 at the lower end thereof, this slot opening at the lower end of the pipe and being rounded at its upper or closed end. An elongated channel-shaped or U-shaped hose guiding member 40 is pivotally mounted inside standpipe 5, in such a position as to be capable of moving inwardly and outwardly through slot 39. This pivotal mounting is effected by means of a pair of dia-v metrically-opposite pivot screws 41 (FIG. 5) whose heads are rotatably mounted in respective diametrically-opposite holes in standpipe 5 and whose Shanks thread tightly into respective tapped holes provided in the opposite side walls of member 40, near the inner end of this member. At the inner or pivoted end of member 49, the side walls of this member extend somewhat beyond the base or bottom wall of the U. In order to provide clearance for the inner ends of these side walls, a pair of internal grooves 42 are provided in the wall of standpipe 5 opposite slot 39, these grooves being aligned respectively with the side walls of slot 39. The pivotal mounting of member 40 in standpipe 5 allows this member to be rotated (the member then movin in the inward direction through slot 39, toward a position wherein its length extends more or less parallel to the axis of pipe 5) a suicient amount to allow pipe 5 to be pushed downwardly through pipe 3.

At the outer or free end of member 40 (that is, at the end thereof opposite the pivots 41), the side walls of this member extend beyond the base or bottom wall thereof to provide a shoe portion 49a at the outer end of the member, the edges of these side walls extending upwardly and outwardly at an angle of about 30 from the plane of the base of the U. This causes the upper faces of the side walls of this member to project some distance beyond the termination or end of the bottom wall of the U. This is shown in FIG. l, and the reason for it will become apparent hereinafter.

Means are provided for resiliently biasing the hose guiding member 40 to swing outwardly about its pivots 41, away from the axis of pipe 5. This means comprises a thin member 43 made of spring steel and formed into an arcuate shape at one end. The flat upper end of the pivot spring member 43 is fastened to the inner wall of pipe 5 by means of a pair of vertically-spaced rivets 44 which are located slightly above the pivot screws 41, a semielliptical ller member 45 being interposed between the spring 43 and the inner cylindrical wall of pipe S, to provide a planar mounting surface for the planar surface of the spring. The width of the flat or leaf spring 43 is slightly less than that of the bottom wall of the U member 40, and the outer surface of this spring bears against the bottom wall of member 40. The lower or free end of spring 43 is curved outwardly, away from the wall to which the upper end of the spring is secured and toward the slot 39. Thus, the spring 43 acts to resiliently bias member 4I) away from the axis of pipe 5 and outwardly through slot 39.

In setting up the apparatus of this invention for use,

the cap is first removed from the upper end of the gauge tube 3 of the tank to be cleaned. Then, the standpipe 5 is brought up to the gauge tube, with the guiding member 40 end of the pipe lowermost. The guiding member 40 is then swung inwardly (i.e., toward the axis of pipe 5), about its pivots and against the bias of spring 43, to a degree suicient to allow the lower end of pipe 5 to be inserted into tube 3. The slot 39 in pipe 5 allows the member 40 to swing inwardly in this manner. After this has been done, the standpipe 5 is inserted into tube 3, with the slotted end 31 of pipe 5 uppermost, and is pushed down vertically through tube 3, and on through the interior of the tank, until the lower end of standpipe 5 contacts the tank bottom 1. As the lower end of standpipe 5 emerges from the lower end of gauge tube 3, at the top of the tank, the biasing effect of spring 43 on member 40 causes the latter to swing outwardly (through slot 39), away from the axis of the pipe 5. Thereafter, as the lower end of standpipe 5 approaches the tank bottom 1, the shoe portion 40a of member 40 comes into Contact with the tank bottom and, as standpipe 5 moves further downwardly, the hose guiding member 40 is swung further outwardly until, at the lower limit of travel of pipe 5 (i.e., when its lower end engages the tank bottom 1), the hose guiding member makes an angle of about 60 with the axis of pipe 5.

After standpipe 5 has been put into position in the aforesaid manner, the loaded reel 12 is brought up to the standpipe 5 (whose upper end extends above ground level 2, as previously stated), and is secured to the upper end of pipe 5 by tightening the handle 29. Then, the keeper spring hook 26 is released and the nozzle or free end of the hose assembly 4 is inserted into the upper end of standpipe S, and the hose assembly is pushed downwardly through pipe 5. This can readily be done since the hose assembly 4 has a substantial degree of stiffness in the direction of its length. Of course, the reel 12 rotates about its substantially horizontal axis to unwind the hose assembly therefrom as the latter moves downwardly through pipe 5.

As the hose assembly approaches the lower end of standpipe 5, the nozzle 6, and then the hose assembly 4 itself, comes into contact with the bottom wall of the hose guiding member 411, causing the nozzle and the hose assembly to be guided by this member laterally outwardly (through slot 39, and away from the axis of pipe 5) and downwardly to lie along the bottom 1 of the tank, as illustrated in FIG. l.

When the nozzle has reached the guiding member 40, the suction pump is connected to conduit 23 at the surface and is started up (if this has not already been done). Then, the hose assembly 4 i-s pushed further downwardly to cause nozzle 6 to move outwardly fro-m pipe 5 and horizontally along the tank bottom 1. Sludge, sediment, water, etc., are then drawn up by the pump from the bottom of the tank as the nozzle moves in a substantially straight line horizontally along the bottom of the tank, away from pipe 5. The operator, -by watching sight tube 21, may determine when the cleaning process has been completed, Then, the hose is reeled in until the nozzle 6 is within the contines of pipe 5.

Thereafter, the reel 12 is rotated slightly in azimuth (i.e., it is rotated bodily in a horizontal plane) to cause the pipe 5 and the hose guiding member 40 to rotate to a slightly different angular position relative to the tank bottom 1, so that another cleaning swipe may be effected as the hose is again pushed downwardly and is guided by member 40 to follow a slightly different straight-line path along the tank bottom 1. In this connection, it is pointed out that, since slot 31 in pipe 5 is diametrically opposite to slot 39 and since the reel 12 is always (as a result of pin 3@ fitting within slot 31) mounted in the same angular position with respect to slot 3-1, the azimuthal position of reel 12 serves to indicate, at the surface, the azimuthal direction of hose guiding member 40, and consequently the direction fo travel of hose assembly 4 as the latter,

guided by member 40, moves outwardly from pipe along the tank bottom 1.

After the entire cleaning operation has been completed, the hose assembly 4 is reeled in and the reel is uncoupled from pipe S. After the hose reel has been removed from pipe 5, the latter is drawn upwardly, out of gauge tube 3. The pivotal mounting of guiding member 4t) in pipe 5 enables this member to swing into pipe 5 sufficiently to permit the pipe to be readily withdrawn from tube 3.

The invention claimed is:

1. In apparatus for cleaning a tank through an opening near the top thereof, a substantially rigid standpipe adapted to be lowered through said opening into contact with the bottom of the tank, an elongated hose guiding member having one end thereof pivotally connected to said pipe within the same at a location near the lower end thereof, said guiding member being constructed and arranged to swing outwardly with respect to said pipe beyond the contines thereof and to extend downwardly from its pivot at an arcuate angle to the axis of said pipe when the free end of said member and the lower end of said pipe are in contact with the tank bottom; and means for resiliently biasing said member to swing outwardly about its pivot, away from said pipe.

2. Apparatus as defined in claim 1, wherein said acute angle is not in excess of approximately 60.

3. In apparatus for cleaning a tank through an opening near the top thereof, a substantially rigid standpipe adapted to be lowered through said opening into contact with the bottom of the tank, said pipe having in its wall an elongated slot opening into the lower end of the pipe; and an elongated hose guiding member having one end thereof pivotally connected to said pipe within the same at a location spaced from the lower end thereof, said guiding member being constructed and arranged to swing outwardly through said slot beyond the confines of said pipe and to extend downwardly from its pivot at an angle not in excess of approximately 60 to the axis of said pipe when the free end of said member and the lower end of said pipe are in contact with the tank bottom, whereby an elongated hose, which is flexible yet which possesses substantial stffness in the direction of its length, may be passed down through said standpipe to be guided by said member to a position wherein it extends along the tank bottom.

4. Apparatus in accordance with claim 3, including also means for biasing said member to swing outwardly about its pivot, away from said pipe.

5. In apparatus for cleaning a tank through an opening near the top thereof by means of a hose which is flexible yet which possesses substantial stiffness` in the direction of its length: means for guiding said hose substan tially vertically downwardly through said opening and toward the bottom of the tank, and thence laterally along the bottom thereof, comprising a substantially rigid standpipe adapted to be lowered through said opening into contact with the tank bottom, an elongated hose guiding member having one end thereof pivotally connected to said pipe within the same at a location near the lower end thereof, said guiding member being constructed and arranged to swing outwardly with respect to said pipe beyond the confines thereof and to extend downwardly from its pivot at an acute angle to the axis of said pipe when the free end of said member and the lower end of said -pipe are in contact with the tank bottom; and means for rcsiliently biasing said member to swing outwardly about its pivot, away from said pipe.

6. Apparatus as set forth in claim 5, wherein said acute angle is not in excess of approximately 7. In apparatus for cleaning a tank through an opening near the top thereof by means of a hose which is flexible yet which possesses substantial stiffness in the direction of its length: means for guiding said hose substantially vertically downwardly through said opening and toward the bottom of the tank, and thence laterally along the bottom thereof, comprising a substantially rigid standpipe adapted to be lowered through said opening into contact with the tank bottom, said pipe having in its wall an elongated slot opening into the lower end of the pipe; an elongated hose guiding member having one end thereof pivotally connected to said pipe within the same at a location spaced from the lower end thereof, said guiding member being constructed and arranged to swing outwardly through said slot beyond the contines of said pipe and to extend downwardly from its pivot at an acute angle to the axis of said pipe when the free end of said member and the lower end of said pipe are in contact with the tank bottoni; and means for resiliently biasing said member to swing outwardly about its pivot, away from said pipe.

S. Apparatus as set forth in claim 7, wherein said acute angle is not in excess of approximately 60.

References Cited UNITED STATES PATENTS 1,660,999 2/1928 MacDonell 175-79 2,332,940 lO/ 1943 Senke. 2,358,470 9/1944 Oswald 175-79 X 3,183,940 5/1965 Alquist et al 15-246.5 X

FOREIGN PATENTS 656,111 1/1963 Canada.

ROBERT W. MICHELL, Primary Examiner. 

1. IN APPARATUS FOR CLEANING A TANK THROUGH AN OPENING NEAR THE TOP THEREOF, A SUBSTANTIALLY RIGID STANDPIPE ADAPTED TO BE LOWERED THROUGH SAID OPENING INTO CONTACT WITH THE BOTTOM OF THE TANK, AN ELONGATED HOSE GUIDING MEMBER HAVING ONE END THEREOF PIVOTALLY CONNECTED TO SAID PIPE WITHIN THE SAME AT A LOCATION NEAR THE LOWER END THEREOF, SAID GUIDING MEMBER BEING CONSTRUCTED AND ARRANGED TO SWING OUTWARDLY WITH RESPECT TO SAID PIPE BEYOND THE CONFINES THEREOF AND TO EXTEND DOWNWARDLY FROM ITS PIVOT AT AN ARCUATE ANGLE TO THE AXIS OF SAID PIPE WHEN THE FREE END OF SAID MEMBER AND THE LOWER END OF SAID PIPE ARE IN CONTACT WITH THE TANK BOTTOM; AND MEANS FOR RESILIENTLY BIASING SAID MEMBER TO SWING OUTWARDLY ABOUT ITS PIVOT, AWAY FROM SAID PIPE. 